Protein resistant materials have heretofore been used in a number of applications, such as prostheses, sensors, substrates for enzyme-linked immunosorbent assays (ELISAs), materials for use in contact lenses, and implanted devices. More recent applications include systems for patterned cell cultures, tissue regeneration, microfluidic systems, drug delivery, and systems for high-throughput screening of proteins or cells.
Poly(ethylene glycol) (PEG) is among the most commonly used biomaterials because of its exceptional biocompatibility. PEG is known to be highly resistant to nonspecific protein binding. As a simple main-chain polyether, however, PEG has several limitations. The use of PEG in biomedical applications is, however, limited by the facts that a) PEG can only be functionalized at the chain ends and b) PEG is not biodegradable. For many biomedical applications, biodegradability and the flexibility to incorporate desired functionalities are critical.
Despite extensive research, the molecular mechanism for PEG's protein resistance is not yet fully understood. To generate structure-property correlation and to discover new structures resistant to protein binding, others have prepared self-assembled monolayers (SAM's) presenting substrates with various functional groups to test the protein binding of those substrates. Through those studies, it has been observed that protein resistant substrates exhibit (a) hydrophilicity, (b) the ability to accept hydrogen bonding, (c) the inability to donate hydrogen bonding, and (d) a net neutral charge. See, Ostuni, E.; Chapman, R. G.; Holmlin, R. E.; Takayama, S.; Whitesides, G. M. Langmuir 2001, 17, 5605-5620; Chapman, R. G.; Ostuni, E.; Takayama, S.; Holmlin, R. E.; Yan, L.; Whitesides, G. M. J. Am. Chem. Soc. 2000, 122, 8303-8304; Ostuni, E.; Chapman, R. G.; Liang, M. N.; Meluleni, G.; Pier, G.; Ingber, D. E.; Whitesides, G. M. Langmuir 2001, 17, 6336-6343 and Chapman, R. G.; Ostuni, E.; Yan, L. and Whitesides, G. M. Langmuir 2000, 16, 6927-6936.
There remains a need in the art for the synthesis and development of new protein resistant biomaterials which are biocompatable and/or can be functionalized at sites other than chain ends and/or are biodegradable.